Nucro is very correct, the 700 is actually just a 600 (which is a new chip speed, not just an OC'ed 500) with the internally locked multiplier reset by Intel, kinda like the old 3DFX chips, the voodoo3 3000 ran at 145MHZ, but to get a 3500 you start at 160MHZ, same chips made on the same lines but they test stability of the chips then classify them as 3500 or 3000. Basically to get good results get a 600 or 800, or 533, or even the 566.
i think all the new mobos will happily OC any celeron as it is very OC friendly.
just make sure you have pc100 or might as well get pc133 ram, and buy the better stuff CAS2 is worth the few pennies extra...cant get it cheap by your house? pricewatch can help, they even show prices for pc150 and 166.
good luck